Dual BRP9004 Digital Bass Restoration Processor Maximum input/output levels: 15V RMS/13.5V RMS Signal to noise ratio: -130dB Frequency response: 10Hz  100kHz, +/-1dB and Variable low frequency boost (35Hz ~ 80Hz) Built-in line driver (2V, 5V, 7V, 10V) Under-dash mountable remote control (included)